The present invention relates to an optical communication apparatus used for optical communications.
Recently, an optical communication module for optical communications has been used widespread. In general, such optical communication module is provided with a semiconductor laser and a condenser lens which converges laser light emitted by the semiconductor laser on an entrance surface of an optical fiber.
A type of an optical communication module employed in an ONU (Optical Network Unit) for bidirectional optical communications includes a WDM (Wavelength Division Multiplexing) filter and a light receiving device in addition to the semiconductor laser and the condenser lens.
Such optical components provided in the optical communication module must be accurately aligned with the optical fiber. Typically, in manufacturing process of the optical communication module, such optical components are securely fixed on a base of the optical communication module by welding or by using an adhesive after the optical components are accurately aligned with the optical fiber.
However, even though the optical communication module is fabricated with high accuracy by using the above-mentioned manufacturing process, some problems to be solved arise. Firstly, if the optical components in the optical communication module are fixed by using the adhesive, it can not be determined whether the optical communication module passes or fails a test until the adhesive sets. Further, high production yields of such type of the optical communication module can not be expected due to difficulty of the above-mentioned manufacturing process.
Secondly, if a positional relationship of the optical components in the optical communication module varies with age and therefore performance of the optical communication module deteriorates, the performance of the optical communication module can not be restored because the optical components are securely fixed.
Accordingly, an optical communication module, which is configured to keep high performance and not to cause deterioration of performance depending on environmental conditions such as ambient temperature, mechanical conditions, variation with age and the like, is required.